For the new study, CDC researchers looked at RSV hospital recordings in two different RSV surveillance networks from hospitals and medical centers (called RSV-Net and NVSN). They compared the hospitalization of the networks in the RSV season of 2024-2025 with their respective rates in pre-Pandemic seasons between 2018 and 2020. The analysis showed that in newborns (0-2 months), RSV hospital recordings with 52 percent in NVSN in NVSN in NVSN in NVSN in NVSN in NVSN in NVSN in NVSN in NVSN in NVSN in NVSN in NVSN in NVSN in NVSN in NVSN in NVNSN In NVSN in NVSN in NVSN in NVSN compared to the rates of the period 2018-2020. However, when the researcher excluded data from NVSN's surveillance site in Houston – where the RSV season started from 2024–2035 before the vaccine and the treatment were rolled out – there was a decrease of 71 percent in hospital admissions in NVSN.
For a broader group of infants-0 to 7 months old-donated RSV-Net a decrease of 43 percent in hospital admissions in the RSV season 2024-2025 and NVSN saw a decrease of 28 percent. Again, when Houston was excluded from the NVSN data, there was a decrease of 56 percent.
Finally, the researchers looked at hospitalization for toddlers and children up to 5 years old, who would not have been protected by the new products. There they saw that RSV hospital recordings were higher in the 2024-2025 season than in the pre-Pandemic years. That suggests that the last RSV season was more serious and the drops in hospital admissions can be underestimated.
